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Build: VODER Excitation

The excitation stage of a VODER speech synthesizer. A glottal pulse oscillator (buzz, with -12 dB/oct harmonic rolloff) and a white noise generator (hiss, simulating breath) are crossfaded via MIDI CC1 (Mod Wheel). CC1=0 selects pure buzz for voiced sounds, CC1=127 selects pure hiss for unvoiced fricatives, and intermediate values blend both for voiced fricatives.

Step 1: Add the buzz source

Section titled “Step 1: Add the buzz source”

A glottal pulse oscillator at 130 Hz models the vocal fold vibration with -12 dB/oct harmonic rolloff — the carrier for voiced sounds like vowels and nasals.

Nodes added: ve-osc, ve-buzz

Connections: 1 new

Step 2: Add the hiss source

Section titled “Step 2: Add the hiss source”

White noise simulates turbulent breath for unvoiced fricatives like /s/, /f/, /h/.

Nodes added: ve-noise, ve-hiss

Connections: 1 new

Step 3: Mix excitation sources

Section titled “Step 3: Mix excitation sources”

Both sources feed into a mixer amp. Web Audio sums the two connections automatically.

Nodes added: ve-mix

Connections: 2 new

Step 4: Add CC crossfade

Section titled “Step 4: Add CC crossfade”

MIDI CC1 (Mod Wheel) controls the buzz/hiss blend. The CC value drives noise gain directly (0→1). An invert chain (mul by -1, add 1) creates the complementary buzz gain (1→0).

Nodes added: ve-cc, ve-inv, ve-flip

Connections: 4 new

Step 5: Group into a module

Section titled “Step 5: Group into a module”

Select all eight nodes and press g. Expose the mixer output and pitch parameter.

What you just built

Section titled “What you just built”

A reusable VODER Excitation module with 2 exposed parameters and 1 exposed port.

Select it in the Module Library (SPC m) to add one to any patch.

Next steps

Section titled “Next steps”